Material mixer

ABSTRACT

A plastic mixer of the internal or closed mixing chamber-type having a bladed rotor in the mixing chamber and a material discharge swinging door at the bottom of the mixing chamber, which door is fixed to a shaft oscillatable by a vane-type hydraulic motor and secured in closed position by a slidable bolt reciprocated by a hydraulic motor. The material discharge door is relatively heavy and is moved rapidly by the door operating vanetype motor. The hydraulic system for actuating the door includes a device for controlling deceleration of the door.

United States Patent [151 3,695,587 De Marco 1 Oct. 3, 1972 MATERIAL MIXER 3,099,040 7/1963 Matsuoka ..259/4l X In ento Frank De Marco, Mentor MatSuOlCa Ohm Primary ExaminerRobert W. Jenkins [73] Assignee: Intercole Automation, Inc., Cleve- Attorney-Watts, Hoffmann, Fisher& Heinke land, Ohio [22] Filed: June 18, 1971 [57] ABS 1 CT A plastic mixer of the internal or closed mixing [21] l54407 chamber-type having a bladed rotor in the mixing chamber and a material discharge swinging door at the 52 U.S. Cl ..2s9/41, 259/104 bottom of the mixing chamber, which door is fixed w 51 Int. Cl. ..B0lf 7/08 a Shaft escillamblc y yp hydraulic motor and 5 Field of Search 259/41 6 9 1O 45 4 109 secured in ClOSCCl position by a slidable bolt 5 1 reciprocated by a hydraulic motor. The material discharge door is relatively heavy and is moved rapidly by the door operating vane-type motor. The hydraulic [56] References Cited system for actuating the door includes a device for UNITED STATES PATENTS controlling deceleration of the door. 2,994,100 8/1961 Comes ..259/4l X 7 Claims, 4 Drawing Figures r\\ \\V r \q i L\ Q Q 55 Q o. or I g I l- E fl 4 l 3 P'A'TENTEDnma I972 3.695, 587

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A TTOENE Y5 MATERIAL MIXER 1. Field of the Invention I The invention relates to plastic mixers of the internal or closed mixing chamber-type.

2. Description of the Prior Art Plastic mixers of the internal or closed mixing chamber-type having a material discharge door at the bottom of the mixing chamber fixed to an oscillatable shaft having a hydraulic motor connected thereto are known, see U.S. Pat. No. 3,352,542. The lack of suitable hydraulic door operating mechanism including deceleration of the door as it approached open and/or closed position has resulted in slow and/or otherwise unsatisfactory door operation and/or damage to the equipment.

SUMMARY OF THE INVENTION The present invention provides a material mixer of the internal or closed material mixing type especially suitable for mixing rubber, resins and other plastic and plastic-like material having a material discharge opening in the bottom of the mixing chamber closed by a swinging door fixed to an oscillatable shaft having a vane-type hydraulic motor connected thereto which motor is actuated by a hydraulic system that effects high speed operation of the door and deceleration of the door as it approaches its closed and open position.

The invention further provides a. plastic mixing machine of the closed or internal material working chamber type with a bottom material discharge aperture, opened'and closed by a swinging door powered by a vane-type hydraulic motor controlled by valve means connected to the motor by a pair of conduits one of which includes a portion of increased or enlarged cross-sectional area having a volume preferably slightly smaller than that of one stroke of the vane motor and ports at'opposite ends, a piston slidably supported in the portion of enlarged cross-sectional area provided with tapered projections on opposite sides for selectively restricting the flow 'of fluid through the ports, and bypass conduits by-passing the ports and the piston.

More specificallythe present invention provides a plastic mixing machine of the closed or internal material working chamber type with a bottom material discharge aperture, opened and closed by a swinging door powered by a vane-type hydraulic motor controlled by valve means connected to the motor by a pair of conduits one of which includes a fluid control unit comprising a closed cylinder having ports in its opposite ends, a piston slidably supported in the cylinder having tapered valve projections on opposite sides for selectively restricting the flow offluid through the ports, by-pass conduits by-passing the ports and the piston, and fluid flow adjusting means in at least the bypass conduits about the ports, the cylinder having a volume preferably slightly less than that of one stroke of the vane motor plus that of the piston.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspectivelviewof a plastic mixer embodying the present invention;

.FIG; 2 is a fragmentary sectional view approximately on the line2-2 of FIG. 1;

FIG. 3 is a diagrammatical view of the hydraulic control system; and

FIG. 4 is a sectional view of the deceleration unit shown in FIG. 3.

DESCRIPTION OF PREFERRED EMBODIMENT The invention is herein shown as embodied in a plastic mixing machine designated generally by the reference character A and comprising a housing 10 having a mixing chamber 12 within which plastic material is mixed or otherwise processed by rotors 16, 18 rotatable therein. The material to be mixed is Introduced at the top of the mixing chamber through an opening 20 in the housing 10 which opening is closed during the mixing operation by a ram 22 which normally floats on the material being mixed. The bottom of the mixing chamber is provided with a material discharge opening or aperture 30 closed during the mixing operation by a swinging door member 32 fixed to a shaft 34 rotatably supported by suitable bearings in the housing 10. The opening and closing of the door 32 is effected by a hydraulic motor B which in the present instance is of the vane-type having the vane 36 oscillatable within a chamber 38 in the motor housing 40. The vane is carried by a shaft 42 fixedly connected to the adjacent end of the shaft 34. The door is adapted to be secured in closed position by a slidable bolt 44 adapted to be selectively projected underneath and retracted from an extension 46 on the door 32 by a reciprocating-type doubleacting fluid pressure motor C. The rotors 15, 18 are driven in a suitable manner through a gear reducer 50. The construction of the machine thus far described with the exception of the motor B is similar to the machine disclosed in the afore mentioned U.S. Pat.'No. 3,352,542and is not herein further described.

Fluid pressure is selectively admitted to and the hydraulic. motor 8 within which the vane reciprocates to move the door be'tweenclosed position shown in full lines in FIG. 2 and o-penposition shown in dot-dash lines. Hydraulic fluid under pressure is supplied in the system shown by a motor driven pump 60 the outlet of which is connected by a conduit 62 having two check valves 64, 66 arranged in series to the fluid inlet port of a four-way solenoid-operated valve 68 which controls the motor B The fluid outlet port of the valve is connected by a conduit 70 to the sump 72. An accumulator 74 is connected to the conduit 62 intermediate the check valves 64, 66. The conduit 62 intermediate the check valves 64, 66 is also connected with the fluid inlet port of a second four-way solenoid operated valve which controls the motor C for actuating the bolt 44. The fluid outlet port of the valve 80' is connected by conduits 82 to the pump 72.

The left-hand motor control port of the valve 68, as viewed in FIG. 3 is connected by a firstconduit means, designated generally as D and including conduits 90, 92 and a deceleration device or unit E, the cylinder chamber F of which may be considered an enlarged portion of the conduit means D. The conduit 'extends between the valve 68 and the unit E and connects the left-hand control part of the valve to. the left-hand end of a decelerator device E, the right hand end of which is connected by the conduit 92 to chamber 38 of the motor B at one side of the vane 36. The other motor control port of the valve 68 is connected by a conduit 94 to the chamber 38 of the motor B at the opposite side of the vane 36.

The deceleration device E comprises a free or floating piston 102 within the cylinder chamber F formed by a cylinder member 104 having cylinder heads 106, 108 connected to its opposite ends. The piston 102 includes two tapered valves 110, 112 projecting from opposite sides and held assembled therewith by a flanged tubular member 114 extending through the piston proper and the valves 110, 112 and having a headed fastener 116 threaded on the end opposite the flange. The member 116 has a small aperture 120 therethrough. The valves 110, 112 cooperate with floating valve seats 122, 124 carried by the cylinder heads 106, 108, respectively. The valve seats 122, 124 are held in their respective cylinder heads by split rings 130, 132, respectively. The openings through the valve seats 122, 124 constitute fluid ingress and egress ports or passageways in the conduit means D at opposite ends of the cylinder chamber F within which the piston 102 is supported and movable. The cylinder heads 106, 108 have bypass conduits 134, 136 therein extending around or bypassing the valve seats 122, 124, respectively, that is, the ports in the opposite ends of the cylinder chamber F. The flow of fluid through the by-pass conduits 134, 136 is controlled by adjustable needle valves 140, 142, respectively, by which the cross-section of parts of the by-pass conduits can be varied.

The construction of the apparatus is such that when pressure fluid is supplied to the motor B through the conduit means D the vane 36 is urged in a clockwise direction as viewed in FIG. 3, that is, inthe direction to close the door 32 of the mixing chamber 12. This occurs when the valve 68 is moved to the position shown in FIG. 3. With the valve 68 in the position shown fluid under pressure is admitted through conduit 90 to the left-hand end of chamber F within the cylinder 104 of the decelerator device D, that is, to the port of the chamber at the left side of the floating piston 102. At this time the floating piston is at or adjacent to the lefthand end of the cylinder chamber. As fluid under pressure is admitted to the left-hand end of the cylinder chamber F through the conduit 90 the floating piston 102 is caused to move toward the right forcing fluid from the right-hand end of chamber F and into the conduit 92 and the door closing side of the chamber 38 of motor B. This in turn causes the motor 32 to move towards door closed position.

As the door 32 approaches closed position the floating piston 102 approaches the right-hand end of its stroke and the projecting tapered valve 110 on the right-hand side thereof enters the valve seat 122, that is, the port in the right-hand end of chamber F, to restrict and subsequently stop the flow of fluid from the right-hand end of the chamber through the valve seat As the right-hand end of the valve 110 enters the valve seat 122 deceleration of the door begins. If the door has not closed completely before the valve 110 has closed the opening through the valve seat 122 the flow of pressure fluid to the conduit 94 and the motor B is continued through the aperture 120 in the piston 102 to complete the closing of the door at a decelerated rate. The rate at which fluid flows from the left-hand side of the piston to the right and in turn to the motor B, subsequent to the seating of the valve 110, can be regulated by varying the size of the aperture 120 through the piston; For this purpose, in the embodiment shown, the aperture 120 is in the detachable member 116 threaded into one end of a tubular member thus making it easy to substitute members having various size apertures therethrough. As an alternative construction to the use of an aperture through the piston an external unit by-pass may be connected between the conduits 90, 94. After the door 32'is closed it is secured in closed position by operation of the valve to project the bolt 44 therebeneath.

The maximum volume of the chamber F of the deceleration device D at either side of the piston 102 is approximately the same as the volume of liquid required by the motor B to close or open the door 32. The taper of the valves 110, 112 is very small, for example, 0.001 inch per inch with the result that the piston has considerable travel after the flow of fluid from the chamber 152 to the motor B is restricted by the valve before the valve seats. The construction allows the door to move at a very high rate of speed until it closely approaches closed position. The amount of piston movement and in turn high speed and slow speed movements of the door and the rate of deceleration of the door 32 can be adjusted by changing'the length and taper of the valve 110, etc. The deceleration rate can also be varied in the embodiment shown by the adjustable needle valve in a by-pass conduit 134 in the left-hand cylinder head 106 of the deceleration device D which by-passes the port in the left-hand end of the cylinder chamber F, that is, the port controlled by the valve 112. I

When it is desired to open the door the valves 80 and 68 are operated in reverse order to that mentioned above to first withdraw the bolt 44 from beneath the door and subsequently reverse the connection of the fluid pressure and return conduits of the valve 68 to the motor B. The deceleration unit E is now in the fluid return conduit but the sequence and operation of the apparatus is essentially the same as that described with reference to the closing of the door with the vane 36 of the motor B moving in the reverse direction.

With the valve 68 in the reverse position to that shown in FIG. 3, fluid under pressure is admitted to the chamber 38 of the motor B to move the vane 36 in a counterclockwise direction and force fluid from the chamber at the opposite side of the vane 36 through the conduit 92 to the right-hand end or chamber F of the decelerator device E. At this time the floating piston 102 is at or adjacent to. the right-hand end of the chamber. As fluid flows into the right-hand end of chamber F through conduit 92 the floating piston 102 is caused to move toward the left and fluid from the left-hand end of chamber F flows through the valve seat 124 to the sump. This in turn allows the door 32 to move towards open position.

As the door 32 approaches open position the floating piston 102 approached the left-hand end of its stroke and the projecting tapered valve 112 on the left-hand side of the piston entered the valve seat 124 to restrict and then stop flow of fluid from the left-hand end of the cylinder through the port therein, that is, the opening in the valve seat 124. Due to inertia of the door 32 considerable back pressure is built up in the conduit 92 as the valve 112 moves towards closed position with the seat thus decelerating the door. In event the door 32 is not completely open when the valve 112 seats against the valve seat 124 thus preventing further movement of the piston 102 fluid from the left-hand end of chamber F and the exchaust or return fluid side of the vane 36 of the motor B flows slowly through the aperture 120 until the door is completely open.

The door moves at a very high rate of speed until it closely approaches open position. The amount of piston movement and in turn high speed door movement and the deceleration movement of the door 32 as it moves to open position can be adjusted by changing the length and taper of the valve 112, etc. The deceleration rate can also be varied by the adjustable needle valve 142 in a by-pass conduit 136 in the lefthand cylinder head 108 of the deceleration device D.

While the preferred embodiment of the invention has been shown and described in considerable detail it is to be understood that the invention may be otherwise embodied and that various modifications in the embodiment shown may be made, such as, other fluid control valves than those shown may be employed and either manually or automatically operated, etc., and it is the intention to hereby cover all modifications and adaptations of the apparatus disclosed coming within the practice of those skilled in the art to which the invention relates.

Having thus described my invention, what I claim is:

1. ln a plastic mixing machine having a material working chamber with a material discharge opening in the bottom selectively closed by a swinging door member, a door closing and opening mechanism for effecting rapid movement of the door member between closed and open position without slamming comprising: a vane-type hydraulic motor connected to said door member for oscillating said door member between closed and open positions, valve means for controlling the flow of hydraulic fluid to and fromsaid motor, a pair of conduit means connecting saidvalve means to said motor, one of said conduit means having a portion thereof of increased cross-sectional area, a piston slidably supported in said portion of increased crosssectional area of said one conduit means and including projections on its opposite sides selectively extensible into portions of said one conduit means adjacent to said portion of increased cross-sectional area upon reciprocation of said piston, said one conduit means including by-pass conduits about said portions thereof immediately adjacent to said portion of increased crosssectional area and a by-pass conduit about said piston, and fluid flow adjusting means in at least said by-pass conduits about said portions of said conduit means immediately adjacent to said portion of increased crosssectional area.

2. In a plastic mixing machine having a material working chamber with a material discharge opening in the bottom selectively closed by a swinging door member, a door closing and opening mechanism for effecting rapid movement of the door member from open to closed position and vise versa without slamming comprising: a vane-type hydraulic motor connected to said door member for oscillating said door member between closed and open positions, valve means for controlling the flow of hydraulic fluid to and from said motor, a pair of conduit means connecting said valve means to said motor, one of said conduit means being connected to the vane chamber of said motor at the end thereof from which said vane moves upon closing of said door member and having a portion thereof of increased cross-sectional area, a piston slidably supported in said portion of increased cross-sectional area of said one conduit means and including projections on its opposite sides selectively extensible into passageways of said one conduit means adjacent to said portion of increased cross-sectional area upon reciprocation of said piston, said one conduit means including by-pass conduits about said passageways and a by-pass conduit about said piston, and means in at least said bypass conduits about said passageways for changing the cross-sectional area of parts thereof.

3. In a plastic mixing machine having a material working chamber with a material discharge opening in the bottom selectively closed by a swinging door member, a door closing and opening mechanism for effecting rapid movement of the door member from open to closed position and vise versa without slamming comprising:

a vane-type hydraulic motor connected to said door member for oscillating said door member between closed and open positions, valve means for controlling the flow of hydraulic fluid to and from said motor, a pair of conduit means connecting said valve means to said motor, one of said conduit means being connected to the vane chamber of said motor at the end thereof from which said vane moves upon closing of said door member and having a portion thereof of increased cross-sectional area, a piston slidably supported in said portion of increased cross-sectional area of said one conduit means and including projections on its opposite sides selectively extensible into passageways of said one conduit means adjacent to said portion of increased cross-sectional area upon reciprocation of said piston, said portion of increased cross-sectional area of said one conduit means having a volume about equal to one stroke of said motor plus the volume of said piston, said one conduit means including by-pass conduits about said passageways and a by-pass conduit about said piston, and means in at least said by-pass conduits about said passageways for changing the cross-sectional area of parts thereof.

4. In a plastic mixing machine, a housing having a material working chamber therein with a bottom material discharge opening, a swinging door member for closing said discharge opening, a vane-type hydraulic motor for oscillating said door member between closed and open positions, valve means for controlling the flow of hydraulic fluid to and from said motor, a pair of conduit means connecting said valve means to said motor, one of said conduit means including a fluid control chamber having fluid ingress and egress parts in its opposite ends, a piston slidably supported in said control chamber and having valve members projecting from opposite sides selectively engageable in said ports.

5. A mixing machine as claimed in claim 4 in which said control chamber has a volume about equal to that of one stroke of said motor plus the volume of said piston.

control chamber and having members projecting from opposite sides selectively engageable in said ports, said one conduit means including by-pass conduits about said ports and a by-pass conduit about said piston, and fluid flow adjusting means in said by-pass conduits about said ports.

7. A mixing machine as claimed in claim 5 in which said control chamber has a volume about equal to that of one stroke of said motor plus the' volume of said piston. 

1. In a plastic mixing machine having a material working chamber with a material discharge opening in the bottom selectively closed by a swinging door member, a Door closing and opening mechanism for effecting rapid movement of the door member between closed and open position without slamming comprising: a vane-type hydraulic motor connected to said door member for oscillating said door member between closed and open positions, valve means for controlling the flow of hydraulic fluid to and from said motor, a pair of conduit means connecting said valve means to said motor, one of said conduit means having a portion thereof of increased cross-sectional area, a piston slidably supported in said portion of increased cross-sectional area of said one conduit means and including projections on its opposite sides selectively extensible into portions of said one conduit means adjacent to said portion of increased cross-sectional area upon reciprocation of said piston, said one conduit means including by-pass conduits about said portions thereof immediately adjacent to said portion of increased cross-sectional area and a by-pass conduit about said piston, and fluid flow adjusting means in at least said by-pass conduits about said portions of said conduit means immediately adjacent to said portion of increased crosssectional area.
 2. In a plastic mixing machine having a material working chamber with a material discharge opening in the bottom selectively closed by a swinging door member, a door closing and opening mechanism for effecting rapid movement of the door member from open to closed position and vise versa without slamming comprising: a vane-type hydraulic motor connected to said door member for oscillating said door member between closed and open positions, valve means for controlling the flow of hydraulic fluid to and from said motor, a pair of conduit means connecting said valve means to said motor, one of said conduit means being connected to the vane chamber of said motor at the end thereof from which said vane moves upon closing of said door member and having a portion thereof of increased cross-sectional area, a piston slidably supported in said portion of increased cross-sectional area of said one conduit means and including projections on its opposite sides selectively extensible into passageways of said one conduit means adjacent to said portion of increased cross-sectional area upon reciprocation of said piston, said one conduit means including by-pass conduits about said passageways and a by-pass conduit about said piston, and means in at least said by-pass conduits about said passageways for changing the cross-sectional area of parts thereof.
 3. In a plastic mixing machine having a material working chamber with a material discharge opening in the bottom selectively closed by a swinging door member, a door closing and opening mechanism for effecting rapid movement of the door member from open to closed position and vise versa without slamming comprising: a vane-type hydraulic motor connected to said door member for oscillating said door member between closed and open positions, valve means for controlling the flow of hydraulic fluid to and from said motor, a pair of conduit means connecting said valve means to said motor, one of said conduit means being connected to the vane chamber of said motor at the end thereof from which said vane moves upon closing of said door member and having a portion thereof of increased cross-sectional area, a piston slidably supported in said portion of increased cross-sectional area of said one conduit means and including projections on its opposite sides selectively extensible into passageways of said one conduit means adjacent to said portion of increased cross-sectional area upon reciprocation of said piston, said portion of increased cross-sectional area of said one conduit means having a volume about equal to one stroke of said motor plus the volume of said piston, said one conduit means including by-pass conduits about said passageways and a by-pass conduit about said piston, and means in at least said by-pass conduits about said passageways for changing the cross-sectional area of pArts thereof.
 4. In a plastic mixing machine, a housing having a material working chamber therein with a bottom material discharge opening, a swinging door member for closing said discharge opening, a vane-type hydraulic motor for oscillating said door member between closed and open positions, valve means for controlling the flow of hydraulic fluid to and from said motor, a pair of conduit means connecting said valve means to said motor, one of said conduit means including a fluid control chamber having fluid ingress and egress parts in its opposite ends, a piston slidably supported in said control chamber and having valve members projecting from opposite sides selectively engageable in said ports.
 5. A mixing machine as claimed in claim 4 in which said control chamber has a volume about equal to that of one stroke of said motor plus the volume of said piston.
 6. In a plastic mixing machine, a housing having a material working chamber therein with a bottom material discharge opening, a swinging door member for closing said discharge opening, a vane-type hydraulic motor for oscillating said door member between closed and open positions, valve means for controlling the flow of hydraulic fluid to and from said motor, a pair of conduit means connecting said valve means to said motor, one of said conduit means including a fluid control chamber having fluid ingress and egress ports in its opposite ends, a piston slidably supported in said control chamber and having members projecting from opposite sides selectively engageable in said ports, said one conduit means including by-pass conduits about said ports and a by-pass conduit about said piston, and fluid flow adjusting means in said by-pass conduits about said ports.
 7. A mixing machine as claimed in claim 5 in which said control chamber has a volume about equal to that of one stroke of said motor plus the volume of said piston. 